Dynorphin A is a dynorphin, an endogenous opioid peptide with the amino acid sequence: Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys.
Dinorfin A1–8 is a truncated form of dynorphin A with the amino acid sequence: Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile.Dinorfin A1–8 is an agonist at the mu-, kappa-, and delta-opioid receptors,it has the highest binding affinity for the kappa-opioid receptor.
Dinorfin A (1-13) exposure (33 μM) causes a significant loss in neuronal viability at 4 h with a visible destruction in neuronal morphology seen at 16 h. Exposure to dynorphin A (1-13) causes acute increases in [Ca2+]i in individual neurons similar to increases seen with acute NMDA treatment. Continuous exposure to dynorphin A (1-13) (100 μM) causes a significant loss of neurons over time.
